Mold?
 

Hi

So last October I purchased my first ever orchid. This came as a surprise to me as I’ve always had a bit of a black thumb. Also as I have poor impulse control my first orchid was actually a collection of 12 different varieties. So after a lot of time on the internet and a lot of teasing from my husband I set out to keep them alive for as long as possible.

While I was looking through the internet I came across photos of mounted orchids and I fell in love. So 11 of my orchids are mounted.The first challenge that I faced was actually the humidity I live in Edmonton and the winters are very cold and very dry. The solution that I came up with is to keep them in a aquarium with some water to help increase the humidity and to allow me too keep them under lights as natural sunlight in not really a practical option. Time went on and I discovered that maybe I’m not terrible at this. A few of them have bloomed most have put out new roots overall their doing pretty good.

Which brings me to my problem, mold. I have acquired a white powdery substance on most of my wood, it hasn’t yet reached the plants and I hope to keep it that way. My wood is large pieces of non-determinable origin and the plants have been mounted to it for 7 months so I’m not wanting to disturb them.

If anyone has any suggestions I would love to hear from you.

Photos? If it is a mold or mildew, spraying the mounts with a solution of Physan or similar fungicide should knock it down, and shouldn't harm the plants.

Photo
 

I will try to get you some pictures

Here we go
 

Photos

I see that sort of thing growing on mounts that stay rather wet, and don't worry about it. Probably an algae. However, my plants are either outside or in greenhouse, with very good air circulation and exchange. In your closed system maybe it is more of an issue, forum members who grow in terrariums will need to weigh in on this. But Physan should take care of it if it's a concern. It's a quaternary ammonium algicide/fungicide, if diluted according to directions and sprayed on the mounts should not be at all harmful to the plants. Easy to order on Amazon.

Thank you
 

I’ve heard good things about Physan but I haven’t tried it yet. There are vents on the top above the aquarium and I run some fans to keep the air moving. I don’t suppose you know anything about how fish would react to Physan? One of my pieces of wood is partly submersed so cross contamination is unavoidable.

Fish, NO, NO. Physan is deadly to fish! So if fish are anywhere nearby, don't use it! For plants it's fine. Doesn't hurt birds or mammals. But it attacks the mucus that protects the gills of fish, so absolutely not around them!

Fish
 

Lol that’s good too know. The water was there and I had all the equipment so I put guppies in about a month ago. My life would be easier if I hadn’t but well their cute. I did find a fungicide that is ok with the fish but it doesn’t do much for the mold. I also tried tea tree oil and that works wonderful on the mold but if it gets too close to the orchids they will probably die. I am hoping to find a solution but I’m not actually sure there is one.